Run in docker

[reuvenharrison]

Amended readme with option to run in docker. It's useful when you want to automate the artifact validation in a CI pipeline and you don't have Python 3.6 on the VM/container that is running the pipeline. The docker wrapper is here: https://github.com/Tufin/operator-courier The docker image is here: https://hub.docker.com/r/tufin/operator-courier

[kevinrizza]

@reuvenharrison This is nice. Could you add the dockerfile to the PR so that it could be built and amended as part of the release process?

[kevinrizza]

Also please squash commits.

[reuvenharrison]

Applied your feedback. Please remember to update the image name in the readme after you build it yourself (currently points to the image I built).

[kevinrizza]

@reuvenharrison Sorry, I was unclear in my previous request. I meant that, instead of pointing at all to your locally built image directly, could you just provide the dockerfile and some documentation around building and using it locally? Then, if it works well we can create a followup pr with the image built as part of the build process.

I also liked @MartinBasti 's suggestion about pulling down the source and creating the binary at build time, since then we can version the container image rather than always having the latest at runtime.

[reuvenharrison]

Changed Dockerfile to install operator-courier from the local dir. To build the image: docker build operator-courier . To use the container: docker run <image-name> operator-courier ...

[kevinrizza]

/lgtm